Subcutaneous injection of a bortezomib-loaded thermosensitive hydrogel for the treatment of multiple myeloma

[Display omitted] •The PCEC@BTZ/PLEL thermosensitive hydrogel displayed the excellent sol–gel transition behavior.•It could lower the side effects, enhance the therapeutic effect, and reduce the injection time for the MM therapy.•A subcutaneous delivery system of BTZ for a long time may be a potential therapy method for MM.•It expanded the application of hydrogels in tumor therapy, not only limited to in situ therapeutic applications.•The study was closely combined with clinical applications about subcutaneous treatment with bortezomib. Multiple myeloma (MM) is incurable as one of the most common hematologic malignancies. Bortezomib (BTZ) is a first-in-class reversible proteasome inhibitor in the clinic for the treatment of MM. BTZ was initially approved for the administrator by only the intravenous injection route in 2003. Then, subcutaneous administration was approved in the US and EU in 2012 in addition to the intravenous injection route. The rates and severity of peripheral neuropathy were significantly lower than those of intravenous injection administration. Injectable thermosensitive hydrogels are a potential drug delivery system for controlled release. But it is difficult to achieve the aim of local therapy of MM. A subcutaneous delivery system for a long time may be a potential therapy method due to the subcutaneous administration of BTZ. Here, we designed a BTZ-loaded injectable hydrogel system to sustain drug release for a period of days. It could lower the side effects, enhance the therapeutic effect, and reduce the injection time.